Beschreibung:
<jats:p>To improve the understanding of microbial behaviors in communities, proteomic tracking, an approach for relative quantification of species‐specific population dynamics of mixed cultures, was developed. Therefore, a bacterial mixed culture was analyzed during batch cultivations with and without addition of the antibiotic <jats:styled-content style="fixed-case">C</jats:styled-content>eftazidime. The community was composed of <jats:italic><jats:styled-content style="fixed-case">B</jats:styled-content>urkholderia cepacia</jats:italic>, <jats:italic><jats:styled-content style="fixed-case">P</jats:styled-content>seudomonas aeruginosa</jats:italic>, and <jats:italic><jats:styled-content style="fixed-case">S</jats:styled-content>taphylococcus aureus</jats:italic>, pathogens causing infections in cystic fibrosis patients. Gel‐based proteomics and mass spectrometry were used to obtain qualitative and quantitative proteomic data. During cultivation, <jats:italic><jats:styled-content style="fixed-case">P</jats:styled-content>. aeruginosa</jats:italic> became dominant within the mixed culture while <jats:italic><jats:styled-content style="fixed-case">S</jats:styled-content>. aureus</jats:italic> was inhibited in growth. Analysis of samples – taken along cultivation – revealed about 270 differentially expressed proteins. Some of those proteins are related to bacterial interactions, response to antibiotic treatment or metabolic shifts. For instance, the enzymes <jats:styled-content style="fixed-case">P</jats:styled-content>hz<jats:styled-content style="fixed-case">S</jats:styled-content>(flavin‐containing monooxygenase), <jats:styled-content style="fixed-case">P</jats:styled-content>hz<jats:styled-content style="fixed-case">D</jats:styled-content> (phenazine biosynthesis protein), and <jats:styled-content style="fixed-case">P</jats:styled-content>hz<jats:styled-content style="fixed-case">G</jats:styled-content>2 (pyridoxamine 5′‐phosphate oxidase) indicated the production of the antibiotic pigment pyocyanine by <jats:italic><jats:styled-content style="fixed-case">P</jats:styled-content>. aeruginosa</jats:italic> that is related to oxidative stress and therefore, might inhibit growth of <jats:italic><jats:styled-content style="fixed-case">S</jats:styled-content>. aureus</jats:italic>. Overall, the strategy applied not only allows species‐specific tracking of the community composition but also provides valuable insights into the behavior of mixed cultures.</jats:p>